Optical Coherence Tomography (OCT) systems are used to capture and generate images of patient tissue layers. These systems often include OCT probes that can invasively penetrate tissue to obtain visualization of tissue within a patient. In ophthalmology, OCT probes are used to obtain detailed images of tissue about the eye or tissue forming a part of the eye, such as the retina.
The OCT probes often include a projecting cannula that can invasively penetrate patient tissue. The imaging probe scans tissue by refracting the optical light beam through a lens disposed at an end of the cannula. A scanner can steer an imaging light to scan the target tissues. The scanner can be placed at a distal end of the cannula of an OCT probe. Nevertheless, placing the scanner at the distal end of the cannula may cause the size of the distal end of the cannula to be bulky and have complex structure, which is not suitable for insertion into an eye.
As an alternative, the scanner can be placed outside the eye directly above the eye to be able to directly project the imaging light into the eye. Nevertheless, placing the scanner directly above the eye can interfere with an optical pathway of a surgical microscope and can take up essential operating space between the surgical microscope and the eye.
Accordingly, it is beneficial to position the scanner away from the optical pathway of the surgical microscope. For example, the scanner can be placed either in a handpiece of an OCT probe or in a separate scanning unit. If the scanner is placed away from the optical pathway, an optical guide is provided to guide the imaging light back to the cannula that is inserted inside the eye. The optical guide can be a fiber bundle formed by a bundle of optical fibers in order to have certain flexibility. Nevertheless, in a fiber bundle, there are finite gaps formed between the optical fibers. Thus, when an imaging light is scanned across a proximal surface of the fiber bundle, the scanning may be intermittently be interrupted when the imaging light passes through the gaps between the optical fibers. As a result, the output scanning beam can become jumpy, which can cause the scanning image to be grainy and noisy with insufficient resolution.
Accordingly, there is a need for devices, systems, and methods utilizing an OCT imaging system with a scanner scanning a fiber bundle that improve scanning resolution to be finer than a fiber-to-fiber separation of the fiber bundle and that address one or more of the needs discussed above.